Method of making brake shoes



April 24, 1928.

A. Y. DODGE METHOD OF MAKING BRAKE SHOES' 2 Sheets-Sheet Fild July 27.1925 'y ENVENTOR Anm. Y; DODGE 4 er su) Patented Apr. 24, 1928.

UNITED STATES PATENT OFFICE.

ADIEL Y. DODGE, SOUTH BEND, INDIANA, ASSIGNOR TO BENDIX BRAKE COMPANY,OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

METHOD OF MAKING BRAKE SHOES.

Application filed July 27, 1925. Serial No. 46,242.

This invention relates to the manufacture of brake shoes, and will bedescribed as carried out in making shoes of pressed' metal blanks.

'5 Heretofore, in the manufacture of brake shoes of sheet metal, mostearlier shoes having been channel-shaped in cross-section, it has beenthe practice -to have the face of the forming member engage thecylindrical l lining-supporting part, or friction face, of the shoe,which cylindrical face therefore bottoms in the die. When the pressureis relieved, and the formed blank is removed,

'there is invariably more or less return' spring ofthe curved pressedfriction face, andthis -spring is variable and injects an uncontrollablefactor which makes exact results dilicult, many rejections beingnecessary to secure accurate interchangeability ,of the shoes.

According to the present invention, the blanks and shoes are formed by anovel process includingas a very important Step, the pressing of theblanks with the material of the flat shoe web in engagement with theface of the forming member and with the cylindrical flange formed by adrawing action between the` side of the forming meniber and the side ofthe die. As is well known, great accuracy can be secured, in such adrawing action, whilethe web which bottoms in the die, being fiat, hasno uncon- A trollable springto be considered, and

moreover the accuracy of the stilfeningjweb is not very important. t

The above and other objects and novel steps contemplated by theinvention, together with novel features of the formed blanks, will beunderstood from the following description of one application of theinvention as illustrated by the accompanyingdrawings, in which:

Fig. 1 is a vertical section through' they brake, just linside thewheel, showing the shoes in side elevation;

' Fig. 2 is an outside elevation of one of the end shoes, before thebrake lining isI attached; t

Fig. 3 Ais a side elevation of the same shoe; Fig. 4 is a sectionthrough the shoe on the line 4,-4 of Fig. 3; i

Fig. 5 is an inside elevation ofv the shoe; Fig. 6v is a section throughone `Vof the blanks andbthe forming member and die;

Fig. 7 is a similar view showing the use of a different die; and

Fig. 8 1s a plan View of one of the blanks.

In the arrangement of Fig. l, the brake 24. -The shoes are expandedagainst the drum 10 by means such as a double cam 26, y against theresistance of springs 28 and 30.

The shoe 14 is illustrated in Figs. 245, 'and the method of making it inFigs. 6-8; the construction and method of manufacture of the other shoesbeing substantially the same. As best appears in Fig; 4, the shoe isbuilt up of two pressed parts or stampings, made from blanks such as Bin Fig. 8, and each generally L-shaped in cross-section. Thus the twostampings have substantially fiat radial web portions 32, spread apartat the anchored end of the shoe to form parallel arms 34 straddling theend of shoe 16 (Fig. 1) and provided with openings 36 to give ampleclearance for anchor 22.

Around the edge of each stamping runs a continuous flange 38, Wideenough on the outside of the shoe so that the aligned flanges of the twostampings form Ythe friction. face of the shoe and directly support thebrake lining 40 (Fig. 1). The two stampings are' arranged back to backand fastened together, e. g. by means of rivets 42 passing through thetwo web portions 32. A plate 44 may bridge the arms 34 to lengthen thefriction surface and strengthen forming member 60 and a die 62v (Fig. 6)

or 64 (Fig. 7), with the web material 32 in engagement with the face ofthe forming member. Thus the material bottoming -in the die 62, orpushed into the open die 64,

' is the flat web of the blank, which has no Aas tendency to springback, whereas the flange 38, the accuracy of which is highly important,is drawn between the' side of the forming member 60 and the side of thedie 62 or 64. Web 32 is depressed dierent distances into the die, toform the offset arm 34.

While one particular shoe, and one particular way oit' making it, havey.been described in detail, it is not my intention to limit the scope ofthe invention by that description, or otherwise than by the terms of theappended claims.

claim: l. That method of forming pressed meta-l brake shoes whichincludes the steps of cutting integral blanks, each including webmaterial and flange material, and (b) pressing each blank by a formingmember into a die, with the face of the forming member engaging the fiatweb of the shoe and with the opposite sides of the forming membercooperating with the opposite sides of the die to draw out two iangesalono the inner an'd outer edges of said web, he iange along the outeredge being cylindrical.

2. That method of forming pressed metal brake shoes which includes thesteps ,of (a) cutting integral blanks, each including web material andflange material, and (b) pressing each blank by a forming member into adie, with the `face of the forming member engaging the fiat web of theshoe and with the sides of the forming member co-operating With thesidesof the die'to draw out a continuous flange extending entirelyaround the edge of the Web, the parts of said flange along the inner andouter edges of the web beingcurved, and the outer part having a truecylindrical surface.

3. That method of forming pressed metal brake shoes which includes thesteps of (a) cutting integral blanks, each including Web material andangematerial, and (b) pressing each blank by a forming member into adie, with the face of the forming member engaging the flat web of theshoe and With the sides of the forming member co-operating with thesides of the die to draw out a cylindrical flange extending along theouter edge of the web and a substantially radial flange at the end ofthe shoe, and (c) assembling two of the formed blanks back to back andarranging a wear plate across the joint at the end of the shoe andfastening it to said radial flanges.

4. That method of making brake shoe sections Which comprises theoperations of drawing two-reversely contoured sheet metal' parts eachhaving a curved web and a laterally-extending arcuate flange thereon,assemL bling the said parts with the webs back to back at one portion oftheir length and separated at another and with the arcuate flanges inaxial alinement to present a widened support for a brake lining, andconnecting the abutting portions of the 'web to form a unitarystructure.

In testimony whereof l have hereunto signed my name.

ADIEL DODGE.

